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stream
Any body of water, large or small, that flows over the land surface. TERM 2
river
DEFINITION 2 A major branch of a stream system. TERM 3
valley
DEFINITION 3 The entire area between the tops of the slopes on both sides of a stream. TERM 4
channel
DEFINITION 4 A well-defined trough through which the water in a stream flows. TERM 5
floodplain
DEFINITION 5 A flat area about level with the top of a channel that lies on either side of the channel; the part of a valley that is flooded when a stream overflows its banks.
meander
A curve or bend in a stream that develops as the stream erodes the outer bank and deposits sediment against the inner bank. TERM 7
point bar
DEFINITION 7 A curved sandbar deposited along the inside bank of a stream, where the current is weak. TERM 8
oxbow lake
DEFINITION 8 A crescent-shaped, water filled loop created in the former path of a stream when it bypasses a meander and takes a new, shorter course. TERM 9
braided stream
DEFINITION 9 A stream whose channel divides into an interlacing network of channels, which then rejoin in a pattern resembling braids of hair. TERM 10
natural
levee
DEFINITION 10 A ridge of coarse material built up by successive floods that confines a stream within it banks between floods, even when water levels are high.
antecedent stream
A stream that existed before the present topography was created and so maintained its original course despite changes in the structure of the underlying rocks and in the topography. TERM 17
superposed stream
DEFINITION 17 A stream that erodes a gorge in a resistant formation because its course was established at a higher level on uniform rock before downcutting began. TERM 18
abrasion
DEFINITION 18 The erosive action that occurs when suspended and saltating sediment particles move along the bottom and sides of a stream channel. TERM 19
pothole
DEFINITION 19 A hemispherical hole in the bedrock of a streambed, formed by abrasion by small pebbles and cobbles rotating in a swirling eddy. TERM 20
laminar flow
DEFINITION 20 Fluid movement in which straight or gently curved streamlines run parallel to one another without mixing or crossing between layers.
turbulent flow
Fluid movement in which streamlines mix, cross, and form swirls and eddies. TERM 22
suspended load
DEFINITION 22 All the material temporarily or permanently suspended in the flow of a current. TERM 23
bed load
DEFINITION 23 The material a stream carries along its bed by sliding and rolling. TERM 24
competence
DEFINITION 24 The ability of a current to carry material of a given size. TERM 25
capacity
DEFINITION 25 The total sediment load carried by a current.
distributary
A smaller stream that receive water and sediment from the main channel of a river, branches off downstream, and thus distributes the water and sediment into many channels; typically found on a delta. TERM 32
topset bed
DEFINITION 32 A horizontal bed of sediment--typically sand00deposited on top of a delta. TERM 33
foreset bed
DEFINITION 33 A gently inclined deposit of fine-grained sand and silt, resembling large-scale cross-beds, on the outer front of a delta. TERM 34
bottomset bed
DEFINITION 34 A thin, horizontal bed of mud deposited seaward of a delta and then buried by continued delta growth. TERM 35
discharge
DEFINITION 35
- The volume of groundwater leaving an aquifer in a given time. 2) The volume of water that passes a given point in a given time as it flows through a channel of a certain width and depth.
flood
Inundation that occurs when increased discharge, resulting from a short-term imbalance between inflow and outflow, causes a stream to overflow its banks.
